(i) Field of the Invention
The present invention relates to an image projection system wherein in the case that the corresponding images from a plurality of image projection means are independently projected on a dome-shaped screen to create one total combined image on the dome-shaped screen, the joints of the total combined image can be removed finely so that the quality of the total combined image can be enhanced by providing light-shading mechanisms for adjusting the image displaying conditions of the overlapping portions of the total combined image for the image projection means, respectively.
(ii) Description of the Related Art
In an image projection system to display a total image which is obtained by combining a plurality of partial images on a screen, the luminance at the overlapping portion of a plurality of (n) projecting light fluxes is n times (n=2, 3 . . . ) as high as the luminance of the non-overlapping portion, if the image displaying condition of the overlapping portion is not adjusted, so-called “black image rising” are created due to light flux leaks from the light bulbs and the internal leak lights from the optical elements to deteriorate the quality of the total image. In this point of view, such a method is generally available as providing light shading plates for reducing the luminance of the overlapping portion for the image projection means, respectively so that the luminance of the overlapping portions can be set equal to the luminance of the non-overlapping portions.
Such an image projection system as projecting and overlapping the corresponding images from a plurality of image projecting means to display one large-sized image on a dome-shaped screen is proposed (see, Patent Publication No. 1). In the image projection system, four projectors as image projecting means are provided vertically and laterally for the dome-shaped screen so that the light fluxes constituting the partial images from the corresponding projectors are projected diagonally and light shading plates for adjusting the image displaying conditions of the overlapping portions of the partial images are provided for the projectors. The light shading plate are disposed in the spaces between the projectors and the dome-shaped screen.
[Patent Publication No. 1]
Japanese Patent Publication No. 3462470